Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)\[.*\] `) var str = `[03-Jun-2019 11:15:34 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:15:34 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:12 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:12 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:13 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:13 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:14 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:14 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:14 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:15 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:15 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:23 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:24 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:24 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:25 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:25 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:25 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:25 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:25 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:26 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:26 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:26 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:26 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:27 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:27 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:28 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:28 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:29 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:30 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:31 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:31 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:32 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:32 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:32 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:32 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:32 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:32 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:33 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:33 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:33 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:33 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:33 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:34 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:35 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:35 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:35 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:35 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:36 UTC] PHP Notice: Undefined variable: false in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\content-block-builder-functions.php on line 410 [03-Jun-2019 11:16:36 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:36 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:39 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:39 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:39 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:40 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:40 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:40 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:40 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:40 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:40 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:40 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:40 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:40 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:43 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:43 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:43 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:43 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:16:44 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:16:44 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:11 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:12 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:12 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:12 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:13 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:13 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:27 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:28 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:28 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:28 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:28 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:29 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:29 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:29 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:29 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:29 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:42 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:49 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:49 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:50 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:50 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 [03-Jun-2019 11:17:55 UTC] PHP Warning: count(): Parameter must be an array or an object that implements Countable in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\themes\comms-care\functions\mega-menu.php on line 117 [03-Jun-2019 11:17:56 UTC] PHP Notice: Undefined index: key in C:\xampp\htdocs\Comms-Care\site-repo\wordpress\wp-content\plugins\advanced-custom-fields-pro\includes\acf-field-functions.php on line 349 ` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Golang, please visit: https://golang.org/pkg/regexp/